Field of Disclosure
The following relates generally to wireless communication, and more specifically to techniques for random access power level selection for machine type communication (MTC) devices.
Description of Related Art
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems (e.g., a Long Term Evolution (LTE) system).
By way of example, a wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UEs). A base station may communicate with the communication devices on downlink channels (e.g., for transmissions from a base station to a UE) and uplink channels (e.g., for transmissions from a UE to a base station).
Some types of wireless devices may provide for automated communication. Automated wireless devices may include those implementing Machine-to-Machine (M2M) communication or Machine Type Communication (MTC). M2M and/or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station without human intervention. For example, M2M and/or MTC may refer to communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of the information or present the information to humans interacting with the program or application.
MTC devices may be used to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.
In some wireless communications systems, including those employing coverage enhancement techniques, certain channels may have an initial transmission followed by one or more repeated transmissions based on a response, or lack thereof, to the initial transmission. For example, random access transmissions may be initially transmitted, and then retransmitted in the event that a random access response (RAR) is not received. Additionally, power levels for initial transmissions and for certain repeated transmissions may be varied to enhance likelihood of receipt of the transmissions. Efficient determination and adjustment of such power levels may be desirable to provide relatively efficient network access for MTC devices.